lib: update TODO comments

This removes one TODO comment and adds another that indicates that
readline is currently not able to trigger specific escape sequences.

Signed-off-by: Ruben Bridgewater <ruben@bridgewater.de>

PR-URL: https://github.com/nodejs/node/pull/33361


Reviewed-By: Anto Aravinth <anto.aravinth.cse@gmail.com>